Field
This disclosure relates to wireless communications and to passive repeaters for wireless communications.
Description of Related Art
Growing demand for high-rate wireless data services continues to drive the growth of wireless networks. One factor fostering the rapid growth of wireless networks is the growing demand for high-rate data services to be accessible from virtually any location, at all times.
However, despite the efforts of network operators and consumer equipment makers to provide seamless wireless communication coverage, areas of weak signal strength still exist, even in richly serviced areas such as urban centers. The areas of weak signal strength, sometimes referred to as null spots or dead spots, are sometimes caused by the density and material composition of vehicles, buildings and other structures in a wireless coverage area. For example, within a substantially enclosed environment, such as a vehicle or building, the materials of the vehicle or building can cause shadowing, shielding and/or multipath interference that deteriorate radio frequency (RF) signals.
In a vehicle or building, for example, the metal body and/or frame of a vehicle or structural metal and/or reflective windows of a building creates a shielding effect that attenuates radio signals within the vehicle or building. In a dense urban area, the surrounding buildings create a multipath environment where signal reflections destructively combine in locations that are difficult to predict. The destructive interference reduces receivable RF signals to the point where wireless communication can be virtually impossible at the frequency and power levels used in the wireless system. In other situations, the structures themselves acts as barriers that significantly attenuate signal strength of RF signals to the point where the RF signal strength within the structure is lower than is desirable for reliable service.